1. Technical Field
The present disclosure relates generally to input technology for electronic devices using a pen input device.
2. Description of the Related Art
Today's hand held electronic devices such as smart phones, tablets computers, and the like, receive a user's input through various input methods and devices. In particular, the touch screen has become the predominant input mechanism in a majority of devices. Touch screen applications that have recently gained in popularity include handwriting and painting applications in which detection of a user's touch across the touch screen surface is converted to a writing or an image. In these applications, methods and devices for a touch input using a tool instead of the user's finger have been steadily researched and developed in order to allow a more delicate input.
Currently, sophisticated pen input devices which include communication and detection electronics have been proposed for use as a touch input tool. Various techniques have been attempted to measure three dimensional coordinates of these pen input devices by combining an acceleration sensor, an optical sensor, etc. within the pen input device. The coordinates are then used to express the thickness or pressure of a pen input on the basis of measurement results.
However, although there are various effects that can be actually expressed by a pen, it is difficult to vary such effects by simply using the location or tilt of a pen input device without any additional input through a user interface (UI), such as a selection of icons that automatically change a writing expression.
Further, a complex pen input device as mentioned above may often require many measuring units such as sensors equipped therein so as to freely vary expressive effects. This increase in complexity naturally increases the cost of the pen input device.